[Rd] Bug in print.default: dispatches to global show instead of methods::show

Martin Maechler m@ech|er @end|ng |rom @t@t@m@th@ethz@ch
Thu Feb 21 17:29:10 CET 2019


>>>>> Lionel Henry 
>>>>>     on Thu, 21 Feb 2019 12:27:11 +0100 writes:

    > Hello,
    > This is already fixed in r-devel, I think by this commit:

    > https://github.com/wch/r-source/commit/b59a1526085d1b4375b184d35118c6fd6f003912#diff-12de104c9320556f0e99da345c6fb259 <https://github.com/wch/r-source/commit/b59a1526085d1b4375b184d35118c6fd6f003912#diff-12de104c9320556f0e99da345c6fb259>

    > Best,
    > Lionel

Yes, indeed... part of patches that Lionel had proposed himself!

Best,
Martin

    >> On 21 Feb 2019, at 00:07, Dean Attali <daattali using gmail.com> wrote:
    >> 
    >> This is related to a problem that was fixed in 2015
    >> https://github.com/wch/r-source/commit/38ea40dcd0353af16d35296ee621338c49ae48c9
    >> The problem then was that auto-printing by typing an object to the console
    >> would search for show() in the globalenv instead of in the methods
    >> namespace.
    >> 
    >> The problem I would like to report is that it seems that when an S4 object
    >> is printed with print(), a similar issue happens. I do realize that S4
    >> objects should be printed with show() rather than print(), which would
    >> solve the issue, but this still seems like a bug to me.
    >> 
    >> Example:
    >> 
    >> library(methods)
    >> show <- function(...) message("hijacked!")
    >> setClass("Test", representation(test = "character"))
    >> test <- new("Test")
    >> print(test)
    >> # hijacked!
    >> 
    >> [[alternative HTML version deleted]]
    >> 
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